Data storage and retrieval systems are used to store information provided by one or more host computer systems. Such data storage and retrieval systems receive requests to write information to one or more secondary storage devices, and requests to retrieve information from those one or more secondary storage devices. Upon receipt of a write request, the system stores information received from a host computer in a data cache. In certain implementations, a copy of that information is also stored in a nonvolatile storage device. Upon receipt of a read request, the system recalls information from the one or more secondary storage devices and moves that information to the data cache. Thus, the system is continuously moving information to and from storage devices, and to and from the data cache.
It is desirable for many data processing applications to remain in continuous, or near continuous, operation. Data processing systems, however, require both scheduled and non-scheduled maintenance to, among other things, repair equipment, replace equipment, and/or upgrade equipment. What is needed is an apparatus and method to install a new component in an information storage and retrieval system, verify the compatibility of that new component, and then place that new component in service, all the while keeping the information storage and retrieval system in normal operation.